Phenoneazo dyes

ABSTRACT

Phenoneazo dyes of the formula ##STR1## where R 1  is substituted or unsubstituted C 1  -C 4  -alkyl or substituted phenyl, 
     R 2  is cyano, carbamoyl or acetyl, 
     R 3  is substituted or unsubstituted C 1  -C 4  -alkyl or C 3  -C 12  -alkyl which is interrupted by from 1 to 3 oxygen atoms and may be substituted, and 
     R 4  is hydrogen or C 1  -C 4  -alkyl, 
     are useful for thermal transfer processes and for dyeing or printing synthetic fabrics.

The present invention relates to novel phenoneazo dyes of the formula I##STR2## where R¹ is C₁ -C₄ -alkyl which may be C₁ -C₄-alkoxy-substituted or a radical of the formula ##STR3## where L¹, L²and L³ are identical or different and each is independently of theothers hydrogen, C₁ -C₄ -alkyl or C₁ -C₄ -alkoxy,

R² is cyano, carbamoyl or acetyl,

R³ is C₁ -C₄ -alkyl which may be imidazol-1-yl-substituted or C₃ -C₁₂-alkyl which is interrupted by from 1 to 3 oxygen atoms and may besubstituted by C₁ -C₄ -alkanoyloxy, cyclohexyloxy, phenoxy which may beC₁ -C₄ -alkoxy-substituted or phenyl, and

R⁴ is hydrogen or C₁ -C₄ -alkyl, with the proviso that

(a) L¹, L² and L³ are not all hydrogen at one and the same time,

(b) when two of L¹, L² and L³ are hydrogen, the third is C₁ -C₄ -alkoxy,or

(c) when two of L¹, L² and L³ are hydrogen and R³ is CH₂ (C₂ H₄ O)₂ C₆H₅, CH₂ (C₂ H₄ O)₂ C₆ H₁₁ or C₃ H₆ OCH₂ C₆ H₅, the third member of theset may also be isopropyl,

and to a process for the thermal transfer of phenoneazo dyes

DE-A-2 001 821, DE-A-2 157 229 and also EP-A-302 401 already discloseazo dyes where the diazo component is derived from an aminobenzophenoneand the coupling component is a hydroxypyridone.

It is an object of the present invention to provide new phenoneazo dyeswhich are suitable for use as disperse dyes and have advantageousapplication properties.

We have found that this object is achieved by the phenoneazo dyes of theformula I defined at he beginning.

Any alkyl appearing in the phenoneazo dyes of the formula I and in theformula II to be defined hereinafter is either straight-chain orbranched.

R¹, R³, L¹, L² and L³ are each for example methyl, ethyl, propyl,isopropyl, butyl, isobutyl or sec-butyl.

R¹ may also be for example methoxymethyl, ethoxymethyl, 2-methoxyethylor 2-ethoxyethyl.

L¹, L² and L³ may each also be for example methoxy, ethoxy, propoxy,isopropoxy, butoxy, isobutoxy or sec-butoxy.

R³ may also be for example 2-(imidazol-1-yl)ethyl, 2- or3-(imidazol-1-yl)propyl, 2- or 4-(imidazol-1-yl)butyl, 2-methoxyethyl,2-ethoxyethyl, 2-propoxyethyl, 2-isopropoxyethyl, 2-butoxyethyl, 2- or3-methoxypropyl, 2- or 3-ethoxypropyl, 2- or 3-propoxypropyl, 2- or3-butoxypropyl, 2- or 4-methoxybutyl, 2- or 4-ethoxybutyl, 2- or4-propoxybutyl, 2- or 4-butoxybutyl, 3,6-dioxaheptyl, 3,6-dioxaoctyl,4,8-dioxanonyl, 3,7-dioxaoctyl, 3,7-dioxanonyl, 4,7-dioxaoctyl,4,7-dioxanonyl, 4,8-dioxadecyl, 3,6,9-trioxadecyl, 3,6,9-trioxaundecyl,8-acetyloxy-4-oxaoctyl, 3-cyclohexyloxypropyl, 3-benzyloxypropyl or6-phenoxy-4-oxahexyl.

Preference is given to phenoneazo dyes of the formula I where

R¹ is a radical of the formula ##STR4## in which two members of the setL¹, L² and L³ are each hydrogen and the third member is C₁ -C₂ -alkoxyor two members of the set L¹, L² and L³ are each methyl and the third ishydrogen,

R² is cyano,

R⁴ is methyl and

R³ is as defined above.

The phenone dyes of the formula I according to the present invention areprepared in a conventional manner.

For instance, by diazotizing an aminophenone of the formula III ##STR5##where R¹ is as defined above, and coupling it to a pyridone of theformula IV ##STR6## where R², R³ and R⁴ are each as defined above.

The preparation of the aminophenones of the formula III and of thepyridones of the formula IV is known per se and described for example inEP-A-66 153, in previously cited EP-A-302 401 and in the referencesmentioned therein, or they may be prepared by similar methods.

The novel dyes of the formula I are suitable for dyeing or printingsynthetic fabrics, in particular polyester fabrics. The dyeings orprints obtained have good wet fastness and light fastness properties.The novel dyes are notable in particular for their high color strength.

For the abovementioned purposes it is possible to use the novel dyes Inot only as individual components but also as mixtures with one another(for example in a weight ratio of from 50:50 to 99:1).

It is a further object of the present invention to provide a new processfor transferring azo dyes from a transfer to a plastic-coated paper, forwhich the dyes should have the following properties:

ready thermal transferability,

little tendency to migrate within or out of the surface coating of thereceiving medium at room temperature,

high thermal and photochemical stability and also resistance to moistureand chemical agents,

suitable hues for subtractive color mixtures,

a high molar absorption coefficient,

resistance to crystallization on storage of the transfer sheet,

ready industrial availability.

We have found that this object is achieved and that the transfer of azodyes from a transfer to a plastic-coated paper by diffusion with the aidof a thermal printing head is possible to advantageous effect on using atransfer on which there is or are present one or more azo dyes of theformula II ##STR7## where R¹ is C₁ -C₄ -alkyl which may be C₁ -C₄-alkoxy-substituted or a radical of the formula ##STR8## where L¹, L²and L³ are identical or different and each is independently of theothers hydrogen, C₁ -C₄ -alkyl or C₁ -C₄ -alkoxy,

R² is cyano, carbamoyl or acetyl,

X is C₁ -C₄ -alkyl or C₃ -C₁₂ -alkyl which is interrupted by from 1 to 3oxygen atoms and may be substituted by C₁ -C₄ -alkanoyloxy,cyclohexyloxy, phenoxy which may be C₁ -C₄ -alkoxy-substituted orphenyl, and

R⁴ is hydrogen or C₁ -C₄ -alkyl,

with the proviso that L¹, L² and L³ are not all hydrogen at one and thesame time.

To prepare the transfer required for the novel process, the dyes areincorporated into a suitable organic solvent, e.g. chlorobenzene,isobutanol, methyl ethyl ketone, methylene chloride, toluene,tetrahydrofuran or a mixture thereof, together with one or more bindersand with or without the addition of other auxiliaries to form a printingink, in which the dye is preferably present in a molecularly dissolvedform. The printing ink is applied to the inert substrate by knifecoating and the coating is dried in air. Suitable binders are all resinsand polymer materials which are soluble in organic solvents and capableof binding the dye to the inert substrate in such a way that it will notrub off. Preference is given to those binders which, after the printingink has dried in air, hold the dye in the form of a clear, transparentfilm without visible crystallization of the dye.

Examples of such binders are cellulose derivatives, e.g.methylcellulose, ethylcellulose, ethylhydroxyethylcellulose,hydroxypropylcellulose, cellulose acetate or cellulose acetobutyrate,starch, alginates, alkyd resins, vinyl resins, polyvinyl alcohol,polyvinyl acetate, polyvinyl butyrate and polyvinylpyrrolidones. It isalso possible to use polymers and copolymers of acrylates or derivativesthereof, such as polyacrylic acid, polymethyl methacrylate orstyrene-acrylate copolymers, polyester resins, polyamide resins,polyurethane resins or natural CH resins, such as gum arabic. Othersuitable binders are described for example in DE-A-3 524 519.

The preferred binders are ethylcellulose and ethylhydroxyethylcelluloseof medium or low viscosity.

The ratio of binder to dye is preferably within the range from 5:1 to1:1.

Suitable assistants are for example release agents as described inEP-A-227 092, EP-A-192 435 and the patent applications cited therein andalso in particular organic additives which stop the transfer dye fromcrystallizing in the course of storage or heating of the inked ribbon,for example cholesterol or vanillin. Inert substrates are for exampletissue, blotting or parchment paper or plastics films of high heatstability, for example uncoated or metal-coated polyester, polyamide orpolyimide. The inert substrate may additionally be coated on the sidefacing the thermal printing head with a lubricant, or slipping, layer inorder to prevent adhesion of the thermal printing head to the substratematerial. Suitable lubricants are described for example in EP-A-216 483and EP-A-227 095. The thickness of the substrate is in general from 3 to30 μm, preferably from 5 to 10 μm.

Suitable dye receiver layers are basically all temperature stableplastic layers having an affinity for the dyes to be transferred. Theirglass transition temperature should be below 150° C. Examples aremodified polycarbonates and polyesters. Suitable recipes for thereceiver layer composition are described in detail for example inEP-A-227 094, EP-A-133 012, EP-A-133 011, EP-A-111 004, JP-A-199997/1986, JP-A-283 595/1986, JP-A-237 694/1986 and JP-A-127 392/1986.

Transfer is effected by means of a thermal printing head which must beheatable to a temperature ≧300° C. for dye transfer to take place withinthe time interval t: 0<t<15 msec. On heating, the dye migrates out ofthe transfer sheet and diffuses into the surface coat of the receivingmedium.

Details of the preparation may be found in the Examples, the percentagesbeing by weight, unless otherwise stated.

PREPARATION OF DYES Example 1

24.2 g of 4-amino-2-methoxy-5-methylbenzophenone were dissolved in 50 gof N,N-dimethylformamide. The solution was stirred into a mixture of 30ml of concentrated hydrochloric acid, 300 ml of water and 0.5 g of adispersant (addition product of ethylene oxide with oleylamine). Themixture was cooled and diazotized at from 0° to 5° C. by the addition of32.5 ml of a 23% strength by weight sodium nitrite solution. The mixturewas subsequently stirred at from 0° to 5° C. for 2 hours, the excessnitrite was destroyed with amidosulfuric acid, and the diazonium saltwas run into a solution of 32.8 g of the pyridone of the formula##STR9## in 1,000 ml of water and 8 9 of sodium carbonate in such a waythat the pH of the coupling mixture was always >8-ca. 10. Theacid-binding agent used was sodium carbonate. The reaction mixture wasstirred at pH 8.5-9.5 for 2 hours. It was then heated to 50° C. beforeisolation of the dye of the formula ##STR10## Washing with water anddrying left 56.5 g of a yellow powder which forms yellow solutions inN,N-dimethylformamide and acetone and dyes polyester fabric by the HTprocess in deep butter yellow hues of high fastness to thermofixing andof excellent light fastness.

The following dyes are obtained in a similar manner:

                  TABLE 1                                                         ______________________________________                                         ##STR11##                                                                                                              λ.sub.max                                                              [nm]                                                                          in                                  Ex.                                       ace-                                No.  L.sup.1 L.sup.2   L.sup.3                                                                             R            tone                                ______________________________________                                         2   OCH.sub.3                                                                             H         CH.sub.3                                                                            CH.sub.3     432                                  3   OCH.sub.3                                                                             H         CH.sub.3                                                                            C.sub.2 H.sub.5                                                                            432                                  4   OCH.sub.3                                                                             H         CH.sub.3                                                                            C.sub.2 H.sub.4 OCH.sub.3                                                                  432                                  5   OCH.sub.3                                                                             H         CH.sub.3                                                                            C.sub.3 H.sub.6 OCH.sub.3                                                                  432                                  6   OCH.sub.3                                                                             H         CH.sub.3                                                                            C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                           432                                  7   OCH.sub.3                                                                             H         CH.sub.3                                                                            C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                           432                                  8   OCH.sub.3                                                                             H         CH.sub.3                                                                            C.sub.3 H.sub.6 OC.sub.4 H.sub.8                                                           432CH.sub.3                          9   OCH.sub.3                                                                             H         CH.sub.3                                                                            CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                432                                 10   OCH.sub.3                                                                             H         CH.sub.3                                                                            CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                    H.sub.5      432                                 11   OCH.sub.3                                                                             H         CH.sub.3                                                                            CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6                                    H.sub.5      432                                 12   OCH.sub.3                                                                             H         CH.sub.3                                                                            CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.4                                    H.sub.9      432                                 13   OCH.sub.3                                                                             H         CH.sub.3                                                                            CH.sub.2 (C.sub.2 H.sub.4 O).sub.3 C.sub.2                                    H.sub.5      432                                 14   OCH.sub.3                                                                             H         CH.sub.3                                                                             ##STR12##   433                                 15   OCH.sub.3                                                                             H         CH.sub.3                                                                            C.sub.4 H.sub.9 (n)                                                                        432                                 16   OCH.sub.3                                                                             H         CH.sub.3                                                                            C.sub.3 H.sub.6 OCH.sub.2 C.sub.6 H.sub.5                                                  432                                 17   OCH.sub.3                                                                             H         CH.sub.3                                                                             ##STR13##   432                                 18   CH.sub.3                                                                              H         CH.sub.3                                                                             ##STR14##   431                                  18a CH.sub.3                                                                              H         CH.sub.3                                                                            C.sub.4 H.sub.9 (n)                                                                        431                                 19   CH.sub.3                                                                              H         CH.sub.3                                                                            CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6                                    H.sub.5      431                                 20   CH.sub.3                                                                              H         CH.sub.3                                                                            CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                    H.sub.5      431                                 21   CH.sub.3                                                                              H         CH.sub.3                                                                            C.sub.3 H.sub.6 OC.sub.4 H.sub.8 OCOCH.sub.3                                               431                                 22   H       OCH.sub.3 H     CH.sub.3     434                                 23   H       OCH.sub.3 H     C.sub.2 H.sub.5                                                                            434                                 24   H       OCH.sub.3 H     C.sub.2 H.sub.4 OCH.sub.3                                                                  434                                 25   H       OCH.sub.3 H     C.sub.3 H.sub.6 OCH.sub.3                                                                  434                                 26   H       OCH.sub.3 H     C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                           435                                 27   H       OCH.sub.3 H     C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                           433                                 28   H       OCH.sub.3 H     C.sub.3 H.sub.6 OC.sub.4 H.sub.8 OCOCH.sub.3                                               433                                 29   H       OCH.sub.3 H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                433                                 30   H       OCH.sub.3 H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                    H.sub.5      433                                 31   H       OCH.sub.3 H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6                                    H.sub.5      433                                 32   H       OCH.sub.3 H     CH.sub. 2 (C.sub.2 H.sub.4 O).sub.2 C.sub.4                                   H.sub.9      433                                 33   H       OCH.sub.3 H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.3 C.sub.2                                    H.sub.5      433                                 34   H       OCH.sub.3 H                                                                                    ##STR15##   434                                 35   H       OCH.sub.3 H     C.sub.4 H.sub.9 (n)                                                                        433                                 36   H       OCH.sub.3 H     C.sub.3 H.sub.6 OCH.sub.2 C.sub.6 H.sub.5                                                  433                                 37   H       OCH.sub.3 H                                                                                    ##STR16##   433                                 38   H       OCH.sub.3 H                                                                                    ##STR17##   433                                 39   H       OC.sub.2 H.sub.5                                                                        H                                                                                    ##STR18##   433                                 40   H       OC.sub.2 H.sub.5                                                                        H     CH.sub.3     434                                 41   H       OC.sub.2 H.sub.5                                                                        H     C.sub.2 H.sub.5                                                                            434                                 42   H       OC.sub.2 H.sub.5                                                                        H     C.sub.2 H.sub.4 OCH.sub.3                                                                  434                                 43   H       OC.sub.2 H.sub.5                                                                        H     C.sub.3 H.sub.6 OCH.sub.3                                                                  434                                 44   H       OC.sub.2 H.sub.5                                                                        H     C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                           434                                 45   H       OC.sub.2 H.sub.5                                                                        H     C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                           434                                 46   H       OC.sub.2 H.sub.5                                                                        H     C.sub.3 H.sub.6 OC.sub.4 H.sub.8 OCOCH.sub.3                                               434                                 47   H       OC.sub.2 H.sub.5                                                                        H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                434                                 48   H       OC.sub.2 H.sub.5                                                                        H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                    H.sub.5      434                                 49   H       OC.sub.2 H.sub.5                                                                        H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6                                    H.sub.5      434                                 50   H                       CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.4                                    H.sub.9      434                                 51   H       OC.sub.2 H.sub.5                                                                        H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.3 C.sub.2                                    H.sub.5      434                                 52   H       OC.sub.2 H.sub.5                                                                        H                                                                                    ##STR19##   433                                 53   H       OC.sub.2 H.sub.5                                                                        H     C.sub.4 H.sub.9 (n)                                                                        433                                 54   H       OC.sub.2 H.sub.5                                                                        H     C.sub.3 H.sub.6 OCH.sub.2 C.sub.6 H.sub.5                                                  434                                 55   H       OC.sub.2 H.sub.5                                                                        H                                                                                    ##STR20##   433                                 56   CH.sub.3                                                                              OCH.sub.3 H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6                                    H.sub.5      434                                 57   CH.sub.3                                                                              OCH.sub.3 H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                    H.sub.5      434                                 58   CH.sub.3                                                                              H         OCH.sub.3                                                                            ##STR21##   434                                 59   CH.sub.3                                                                              H         OCH.sub.3                                                                           CH.sub.3     435                                 60   CH.sub.3                                                                              H         OCH.sub.3                                                                           C.sub.2 H.sub.5                                                                            434                                 61   CH.sub.3                                                                              H         OCH.sub.3                                                                           C.sub.2 H.sub.4 OCH.sub.3                                                                  435                                 62   CH.sub.3                                                                              H         OCH.sub.3                                                                           C.sub.3 H.sub.6 OCH.sub.3                                                                  435                                 63   CH.sub.3                                                                              H         OCH.sub.3                                                                           C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                           435                                 64   CH.sub.3                                                                              H         OCH.sub.3                                                                           C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                           435                                 65   CH.sub.3                                                                              H         OCH.sub.3                                                                           C.sub.3 H.sub.6 OC.sub.4 H.sub.8 OCOCH.sub.3                                               435                                 66   CH.sub.3                                                                              H         OCH.sub.3                                                                           CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                435                                 67   CH.sub.3                                                                              H         OCH.sub.3                                                                           CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                    H.sub. 5     435                                 68   CH.sub.3                                                                              H         OCH.sub.3                                                                           CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6                                    H.sub.5      435                                 69   CH.sub.3                                                                              H         OCH.sub.3                                                                           CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.4                                    H.sub.9      435                                 70   CH.sub.3                                                                              H         OCH.sub.3                                                                           CH.sub.2 (C.sub.2 H.sub.4 O).sub.3 C.sub.2                                    H.sub.5      435                                 71   CH.sub.3                                                                              H         OCH.sub.3                                                                            ##STR22##   434                                 72   CH.sub.3                                                                              H         OCH.sub.3                                                                           C.sub.4 H.sub.9 (n)                                                                        435                                 73   CH.sub.3                                                                              H         OCH.sub.3                                                                           C.sub.3 H.sub.6 OCH.sub.2 C.sub.6 H.sub.5                                                  435                                 74   CH.sub.3                                                                              H         OCH.sub.3                                                                            ##STR23##   435                                 75   CH.sub.3                                                                              H         OC.sub.2 H.sub.5                                                                    CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6                                    H.sub.5      435                                 76   OCH.sub.3                                                                             CH.sub.3  H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6                                    H.sub.5      432                                 77   CH.sub.3                                                                              CH.sub.3  H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6                                    H.sub.5      431                                 78   CH.sub.3                                                                              CH.sub.3  H     CH.sub.3     432                                 79   CH.sub.3                                                                              CH.sub.3  H     C.sub.2 H.sub.5                                                                            432                                 80   CH.sub.3                                                                              CH.sub.3  H     C.sub.2 H.sub.4 OCH.sub.3                                                                  432                                 81   CH.sub.3                                                                              CH.sub.3  H     C.sub.3 H.sub.6 OCH.sub.3                                                                  432                                 82   CH.sub.3                                                                              CH.sub.3  H     C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                           432                                 83   CH.sub.3                                                                              CH.sub.3  H     C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                           432                                 84   CH.sub.3                                                                              CH.sub.3  H     C.sub.3 H.sub.6 OC.sub.4 H.sub.8 OCOCH.sub.3                                               432                                 85   CH.sub.3                                                                              CH.sub.3  H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                432                                 86   CH.sub.3                                                                              CH.sub.3  H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                    H.sub.5      432                                 87   CH.sub.3                                                                              CH.sub.3  H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6                                    H.sub.5      432                                 88   CH.sub.3                                                                              CH.sub.3  H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.4                                    H.sub.9      432                                 89   CH.sub.3                                                                              CH.sub.3  H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.3 C.sub.2                                    H.sub.5      432                                  89a H       CH.sub.3  CH.sub.3                                                                            CH.sub.3     432                                 90   CH.sub.3                                                                              CH.sub.3  H                                                                                    ##STR24##   431                                 91   CH.sub.3                                                                              CH.sub.3  H     C.sub.4 H.sub.9 (n)                                                                        431                                 92   H       CH.sub.3  OCH.sub.3                                                                           C.sub.3 H.sub.6 OCH.sub.2 C.sub.6 H.sub.5                                                  433                                 93   CH.sub.3                                                                              CH.sub.3  H                                                                                    ##STR25##   432                                 94   H       CH.sub.3  OCH.sub.3                                                                           CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                    H.sub.5      433                                 95   H       CH.sub.3  OCH.sub.3                                                                           C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                           433                                 96   H       CH(CH.sub.3).sub.2                                                                      H     CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6                                    H.sub.5      433                                 97   H       CH(CH.sub.3).sub.2                                                                      H     C.sub.3 H.sub.6 OCH.sub.2 C.sub.6 H.sub.5                                                  433                                 ______________________________________                                    

                                      TABLE 2                                     __________________________________________________________________________     ##STR26##                                                                                                    λ.sub.max [nm]                         Ex. No.                                                                            R.sup.1                                                                              R.sup.2                                                                            R.sup.3   R.sup.4                                                                            in acetone                                    __________________________________________________________________________     98  CH.sub.3                                                                             CN   CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6 H.sub.5                                      H    432                                            99  CH.sub.3                                                                             CN   CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6 H.sub.5                                      CH.sub.3                                                                           431                                           100  CH.sub.3                                                                             CN   CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6 H.sub.5                                      C.sub.3 H.sub.7 (n)                                                                430                                           101  CH.sub.3                                                                             CN   C.sub.3 H.sub.6 OCH.sub.2 C.sub.6 H.sub.5                                               H    432                                           102  CH.sub.3                                                                             CN   C.sub.3 H.sub.6 OCH.sub.2 C.sub.6 H.sub.5                                               CH.sub.3                                                                           431                                           103  CH.sub.3                                                                             CN   C.sub.3 H.sub.6 OCH.sub.2 C.sub.6 H.sub.5                                               C.sub.3 H.sub.7 (n)                                                                430                                           104  CH.sub.3                                                                             CN                                                                                  ##STR27##                                                                              CH.sub.3                                                                           431                                           105  C.sub.2 H.sub.5                                                                      CN   CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6 H.sub.5                                      CH.sub.3                                                                           432                                           106  CH.sub.3                                                                             CN   CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                             CH.sub.3                                                                           431                                           107  CH.sub.3                                                                             CN   CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.2 H.sub.5                                      CH.sub.3                                                                           431                                           108  CH.sub.3 OCH.sub.2                                                                   CN   CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.2 H.sub.5                                      CH.sub.3                                                                           431                                           109  CH.sub.3 OCH.sub.2                                                                   CN   CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6 H.sub.5                                      CH.sub.3                                                                           431                                           110                                                                                 ##STR28##                                                                           CONH.sub.2                                                                         C.sub.2 H.sub.5                                                                         CH.sub.3                                                                            423*                                         111                                                                                 ##STR29##                                                                           CONH.sub.2                                                                         C.sub.4 H.sub.9 (n)                                                                     CH.sub.3                                                                            423*                                         112                                                                                 ##STR30##                                                                           COCH.sub.3                                                                         CH.sub. 3 CH.sub.3                                                                            424*                                         113                                                                                 ##STR31##                                                                           COCH.sub.3                                                                         C.sub.4 H.sub.9 (n)                                                                     CH.sub.3                                                                            424*                                         __________________________________________________________________________     *measured in 9:1 (v/v) N,Ndimethylformamide/glacial acetic acid          

TRANSFER OF DYES

To be able to test the transfer characteristics of the dyes in aquantitative and simple manner, the heat transfer process was carriedout with large hot plates instead of a thermal printing head, thetransfer temperature being varied within the range 70° C.<T<120° C. andthe transfer time being set at 2 minutes.

(A) General recipe for coating the substrates with dye

X g of binder were dissolved in 8 ml (8:2 v/v) of toluene/ethanol atfrom 40° to 50° C. A solution of 0.25 g of dye in 5 ml oftetrahydrofuran was added by stirring. The print paste thus obtained wasapplied with an 80 μm knife to a sheet of polyester film (thickness:6-10 μm) and dried with a hairdryer. (The weight ratio of dye:binder,from which the total amount of binder can be derived, is stated below).

(B) Testing of thermal transferability

The dyes used were tested in the following manner

The polyester sheet donor containing the dye under test on the coatedfront was placed face down on commercial Hitachi Color Video Print Paper(receiver) and pressed down. Donor/receiver were then wrapped inaluminum foil and heated between two hot plates at differenttemperatures T (within the temperature range 70° C.<T<120° C.). Theamount of dye diffusing into the bright plastic layer of the receiver isproportional to the optical density (=absorbance A). The latter wasdetermined photometrically. If the logarithm of the absorbance A of thecolored receiver papers measured within the temperature range from 80°to 110° C. is plotted against the corresponding reciprocal of theabsolute temperature, the result is a straight line whose slope givesthe activation energy ΔE_(T) for the transfer experiment: ##EQU1##

To complete the characterization, it is additionally possible to inferfrom the plots the temperature T*[°C] at which the absorbance A of thecolored receiver papers attains the value 2.

The dyes mentioned below in Tables 3, 4 and 5 were processed accordingto A), and the resulting dyecoated substrates were tested in respect oftheir transfer characteristics by B). The tables list in each case theheat transfer parameters T* and ΔE_(T) and the absorption maxima of thedyes.

In the Examples of Tables 3 and 4, the binder used in each case was amixture of polyvinylbutyrate/ethylcellulose in a weight ratio of 2:1.The weight ratio of binder:dye was 4:1. The λ_(max) values weredetermined on Hitachi Color Video Print Paper.

In the Examples of Table 5, the binder used was ethylcellulose. Theweight ratio of binder:dye was 2:1. The λ_(max) values were determinedin methylene chloride.

                  TABLE 3                                                         ______________________________________                                         ##STR32##                                                                    Ex.                        λ.sub.max                                                                          ΔE.sub.T                         No.  X.sup.1 X.sup.2       [nm]  T*[°C.]                                                                      [kcal/mol]                             ______________________________________                                        114  OCH.sub.3                                                                              ##STR33##    440   92    13                                     115  OCH.sub.3                                                                             C.sub.4 H.sub.9                                                                             444   92    13                                     116  OCH.sub.3                                                                             C.sub.3 H.sub.6 OCH.sub.3                                                                   444   85    13                                     117  OCH.sub.3                                                                             C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                            443   84    15                                     118  OCH.sub.3                                                                             CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 C.sub.6 H.sub.5                                          440   88    12                                     119  CH.sub.3                                                                              C.sub.4 H.sub.9                                                                             439   78    16                                     ______________________________________                                    

                                      TABLE 4                                     __________________________________________________________________________     ##STR34##                                                                    Ex. No.                                                                            X.sup.1      X.sup.2   λ.sub.max [nm]                                                              T*[°C.]                                                                    ΔE.sub.T [kcal/mol]                __________________________________________________________________________    120                                                                                 ##STR35##                                                                                  ##STR36##                                                                              440  96  14                                       121                                                                                 ##STR37##                                                                                  ##STR38##                                                                              440  94  12                                       122                                                                                 ##STR39##                                                                                  ##STR40##                                                                              440  95  17                                       123  CH.sub.3     C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.6 H.sub.5                                       446  98  10                                       124  CH.sub.3     C.sub.3 H.sub.6 OC.sub.2 C.sub.6 H.sub.5                                                440  97  12                                       125  CH.sub.3     C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.2 H.sub.5                                       442  86  15                                       126  CH.sub.3     C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OCH.sub.3                                              438  94  19                                       127  C.sub.2 H.sub.5                                                                            C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.6 H.sub.5                                       438  89  13                                       128                                                                                 ##STR41##   C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                        446  104 17                                       129                                                                                 ##STR42##   C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.2 H.sub.5                                       438  92  19                                       130                                                                                 ##STR43##   C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.6 H.sub.5                                       438  102 16                                       131                                                                                 ##STR44##   C.sub.3 H.sub.6 OCH.sub.3                                                               437  89  13                                       132                                                                                 ##STR45##   C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OCH.sub.3                                              439  104 13                                       133                                                                                 ##STR46##   CH.sub.3 OC.sub.2 H.sub.4 OC.sub.2 H.sub.5                                              439  100 11                                       134                                                                                 ##STR47##   C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                        438  108 13                                       __________________________________________________________________________

                                      TABLE 5                                     __________________________________________________________________________     ##STR48##                                                                    Ex. No.                                                                            X.sup.1      X.sup.2                                                                            X.sup.3   λ.sub.max [nm]                                                              T*[°C.]                                                                    ΔE.sub.T                      __________________________________________________________________________                                              [kcal/mol]                          135                                                                                 ##STR49##   CN   C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                        437  81  20                                  136                                                                                 ##STR50##   CN   C.sub.3 H.sub.6 OCH.sub.3                                                               438  82  21                                  137  C.sub.4 H.sub.9 (n)                                                                        CN   C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.6 H.sub.5                                       431  81  27                                  138                                                                                 ##STR51##   COCH.sub.3                                                                         C.sub.4 H.sub.6 OC.sub.2 H.sub.5                                                        428  81  20                                  139                                                                                 ##STR52##   CN   C.sub.4 H.sub.9 (n)                                                                     431                                          __________________________________________________________________________

We claim:
 1. A phenoneazo dye of the formula I ##STR53## where R¹ is aradical of the formula ##STR54## where L¹, L² and L³ are identical ordifferent and each is independently of the others hydrogen, C₁ -C₄-alkyl or C₁ -C₄ -alkoxy,R² is cyano, carbamoyl or acetyl, R³ is C₄-alkyl or C₃ -C₁₂ -alkyl which is interrupted by from 1 to 3 oxygenatoms and may be substituted by C₁ -C₄ -alkanoyloxy, cyclohexyloxy,phenoxy which may be C₁ -C₄ -alkoxy-substituted or phenyl, and R⁴ ishydrogen or C₁ -C₄ -alkyl,with the proviso that (a) L¹, L², and L³ arenot all hydrogen at one end and the same time, and (b) when two membersof the set L¹, L², and L³ are hydrogen, the third member is C₁ -C₄-alkoxy.
 2. A phenoneazo dye as claimed in claim 1, whereinR¹ is aradical of the formula ##STR55## in which two members of the set L¹, L²and L³ are each hydrogen and the third member is C₁ -C₂ -alkoxy or twomembers of the set L¹, L² and L³ are each methyl and the third ishydrogen, R² is cyano, R⁴ is hydrogen or C₁ -C₂ -alkyl and R³ is asdefined in claim
 1. 3. A phenoneazo dye of the formula ##STR56##
 4. Aphenoneazo dye of the formula ##STR57##